The present invention relates to an electrical connection box, and more particularly, to a vehicular electrical connection box adapted to be selectively attached with an electrical-part mounted unit and enabling a worker to accurately and quickly connect and fit a sharable wire harness at different connecting and fitting locations depending on whether an electrical-part mounted unit has been attached to the connection box.
In recent years, the need for comfort in automobiles has been rising. To satisfy such a need, the general practice has been to provide individual vehicles with options, such as audio systems, navigation systems, television sets, power antennas, air-conditioners, rear window heaters, seat heaters, power seats, suspension hardness control units, and various other electrical components, in accordance with types of vehicles or, even with the same type, in accordance with grades of vehicles.
The wiring for connecting such electrical components with the battery or controller is complicated. Wire harnesses or cables extending from the electrical components, battery, and controller are generally connected to an electrical connection box so as to accurately and simply establish electrical connections between these vehicle-mounted components. Various electrical parts are mounted in the electrical connector box. For example, a fuse is mounted to prevent overcurrent at the time of a short-circuit between a wire harness and a vehicle body or at the time of breakdown of a motor or other electrical component, and a relay is mounted, which cooperates with the operating switch of the electrical component to establish and break a power feed route to an electrical component.
In the case of a vehicle equipped with a large number of electrical components, sometimes an ACG control unit for continuously detecting the amount of power consumed by the electrical components and for controlling the engine speed in accordance with a change in the amount of power consumption is provided in the electrical connection box. In a vehicle equipped with a large number of electrical components, if many of the electrical components are operated at one time, the power consumption increases, the load on the battery rises, and the performance of the electrical components sometimes are lowered, but by controlling the engine speed to one suitable for the power consumption by using the ACG controller, the large number of electrical components can be operated stably.
The ACG control unit attached to the electrical connection box is connected to an engine speed sensor and an engine controller via wire harnesses. Therefore, the manner of wiring in the vehicle differs depending on whether an ACG control unit (more generally, an electrical-part mounted unit) is attached to the electrical connection box. Accordingly, the specifications of the wire harness sometimes vary in accordance with the presence/absence of an ACG control unit. That is, the provision is made of a wire harness having a connector 122 for connection of the ACG control unit (shown at right side in FIG. 5B) and a wire harness not provided with a connector 122 as shown by the two-dot chain line at the right side of FIG. 5A. These two types of wire harnesses are selectively used in accordance with whether the ACG control unit is attached to the connection box. In this case, the types of the wire harnesses increase and the cost rises.
In FIG. 5A and FIG. 5B, reference numeral 111 denotes an ACG control unit holder of the electrical connection box, which holder is formed with a fitting hole 111a into which the ACG control unit 121 having the connector 121c is fitted.
To avoid increased cost caused by the increase in the number of types of wire harnesses, sometimes a wire harness with a tape-insulated connector, serving as a sharable wire harness, is used irrespective of whether an ACG control unit is attached to the electrical connection box. As shown at the right side of FIG. 6A, a wire harness of this kind is provided with a connector 222 employed for connection of the ACG control unit, which connector is covered by an electrically insulating plastic tape 222a. By peeling off the insulating tape 222a from the connector 222, the connector 122 can be connected to a connector of the ACG control unit 121 (FIG. 6B) fitted to the fitting hole 111a of the unit holder 111 of the electrical connection box. On the other hand, when the ACG control unit 121 is not attached to the unit holder 111 of the electrical connection box (shown by the two-dot chain line at the left side of FIG. 6A), it is possible to leave the connector 222 of the wire harness unused in the covered and insulated state (shown at the right side in FIG. 6A).
Since the wire harness of this kind is suitably useable for both the state where the ACG control unit (FIG. 6B) is attached to the connection box and the state where it is not attached thereto (FIG. 6A), such a wire harness may be used as a sharable wire harness to reduce the number of types of wire harnesses. However, to connect the ACG control unit with this wire harness, the extra step of work of peeling off the insulating tape 222a of the connector 222 is required, as shown in FIG. 6B.
To eliminate such inconvenience, it may be considered to form a dummy connector housing near the ACG control unit holder of the electrical connection box. With an electrical connection box of this configuration, it would be possible to fit the wire harness connector to the dummy connector housing when the ACG control unit is not attached to the connection box, while it would be possible to connect the wire harness connector to the connector of the ACG control unit when the ACG control unit is attached thereto. That is, by using a combination of an electrical connection box provided with a dummy connector housing and a wire harness with a connector, a sharable wire harness can be provided, and there is no need to electrically insulate the connector, whereby the labor involved in peeling off the covering tape can be eliminated.
According to the electrical connection box of this configuration, however, even if an ACG control unit (more generally, an electrical-part mounted unit) is attached to the electrical connection box, a worker is liable to mistakenly end up fitting the wire harness connector to the dummy connector housing. In this case, the ACG control unit is not electrically connected with the wire harness, and therefore, the electrical connection box is end up being assembled in a state where the functions of the control unit are prevented from becoming effective. If the electrical connection box assembled with the wire harness connector mistakenly connected in this way were mounted in a vehicle, the mistaken connection would not be discovered before the final inspection line of the vehicle assembly line and the subsequent work for correction would become complicated.
An object of the present invention is to provide an electrical connection box adapted to be selectively attached with an electrical-part mounted unit and enabling a sharable wire harness to be quickly and accurately connected and held at a different connecting and holding location depending on whether the electrical-part mounted unit is attached to the connection box, the sharable wire harness being suitable for use in both the state where the electrical-part mounted unit is attached to the connection box and the state where the unit is not attached.
To achieve the above object, the electrical connection box according to the present invention comprises a unit holder to which an electrical-part mounted unit is adapted to be attached, a dummy connector housing adapted to be fitted with a connector of a wire harness, which connector is employed for connection of the electrical-part mounted unit, and blocking means for preventing the connector from being fitted to the dummy connector housing in a state where the electrical-part mounted unit is attached to the unit holder.
According to the present invention, an ACG control unit or other electrical-part mounted unit can be selectively attached to the electrical connection box, and the wire harness connector can be connected or held without mistake regardless of whether the electrical-part mounted unit is attached to the connection box. That is, in a state where the electrical-part mounted unit is attached to the electrical connection box, the blocking means prevents the wire harness connector from being fitted to the dummy connector housing of the electrical connection box, so that the connector cannot be mistakenly fitted to the dummy connector housing by a worker, whereas the connector is connectable to the electrical-part mounted unit. Thus, the worker accurately connects the connector to the electrical-part mounted unit attached to the electrical connection box. In a state where no electrical-part mounted unit is attached to the electrical connection box, the worker is not permitted to connect the wire harness connector to the electrical-part mounted unit, whereas the connector can be fitted to the dummy connector housing of the electrical connection box. Thus, the wire harness connector is accurately held in the dummy connector housing. In this way, according to the present invention, mistaken connection and mistaken fitting of the wire harness to the electrical connection box can be reliably prevented, thereby making it possible to eliminate the work of inspection for mistaken connection and mistaken fitting and the work of correction.
In the present invention, a wire harness is employed, which is provided with a connector adapted to be connected to the electrical-part mounted unit and to be fitted to the dummy connector housing. This wire harness can be used in common for both the state where the electrical-part mounted unit is attached to the electrical connection box and the state where no electrical-part mounted unit is attached thereto. Since the wire harness is sharable between these states as mentioned in the above, there is no need to selectively use wire harnesses of different specifications in accordance with whether the electrical-part mounted unit is attached, so that the types of the wire harnesses can be decreased, and a contribution to a reduction of costs can be attained.
In addition, there is no need to cover the wire harness connector for insulation. That is, if the dummy connector housing is made from an electrically insulating material, when the wire harness connector is fitted to the dummy connector housing, the connector is insulated from electrical parts located inside and outside of the electrical connection box and from the vehicle body and other conductors. Since the connector does not have to be covered for insulation, there is no need of peeling off an insulating tape from the connector before the wire harness is connected with the electrical-part mounted unit, and therefore, an improvement of the efficiency of the wire harness connection work and a reduction in the number of assembly steps of the electrical connection box can be achieved. This contributes to the reduction of costs.
In the present invention, preferably, the blocking means is comprised of a flexible piece that is formed in the unit holder so as to be able to interact with the electrical-part mounted unit. The flexible piece is displaced, due to interaction between itself and the electrical-part mounted unit, from a first position allowing the connector to be fitted to the dummy connector housing to a second position preventing the connector from being fitted thereto.
With this preferred embodiment, mistaken connection and mistaken fitting of the wire harness connector can be reliably prevented by a simple configuration. That is, if no electrical-part mounted unit is attached to the electrical connection box, the flexible piece cannot interact with the electrical-part mounted unit, so that it assumes the first position. In this case, the flexible piece does not achieve the function of preventing the fitting of the connector, and the electrical-part mounted unit is not attached. Thus, the wire harness connector is connected to the dummy connector housing. On the other hand, if an electrical-part mounted unit is attached to the electrical connection box, the flexible piece is displaced from the first position to the second position due to interaction between itself and the electrical-part mounted unit and achieves the function of preventing the fitting of the connector. That is, the flexible piece prevents the wire harness connector from being fitted to the dummy connector housing, and hence a worker will not mistakenly fit the connector to the dummy connector housing, so that the wire harness connector is connected to the electrical-part mounted unit.
More preferably, the unit holder of the electrical connection box defines a unit fitting space in which the electrical-part mounted unit tightly fits. The dummy connector housing is provided adjacent to the unit holder and defines a connector fitting space in which the connector of the wire harness tightly fits. The flexible piece has a proximal end and a free end. At a location where the unit holder adjoins to the dummy connector housing, the proximal end of the flexible piece is formed integrally with the unit holder. When the flexible piece is at the second position, the free end is displaced into the connector fitting space of the dummy connector housing to thereby prevent the connector from being fitted into the connector fitting space. The flexible piece has an inclined portion on the side of the unit fitting space between the proximal end and the free end. When the flexible piece is at the first position, the inclined portion projects into the unit fitting space. The degree of projection is larger on the free end side.
According to this preferred embodiment, the flexible piece can be formed relatively easily, e.g., by making two cuts in a partition wall between the unit holder and the dummy connector housing. The flexible piece may be provided so as to be able to interact with the electrical-part mounted unit. Further, it is possible to selectively prevent the wire harness connector from being fitted to the dummy connector housing depending on whether the electrical-part mounted unit is attached to the unit holder. That is, if the electrical-part mounted unit is fitted into the unit fitting space of the unit holder, the unit abuts against the inclined portion of the flexible piece located at the first position. If the electrical-part mounted unit is fitted further deeply, the flexible piece is displaced from the first position to the second position by the unit, and the free end of the flexible piece projects into the connector fitting space of the dummy connector housing, thereby preventing the connector from being fitted to the connector fitting space.
In another preferred embodiment of the present invention, the unit holder and the dummy connector housing are arranged adjacent to each other. The unit holder defines a unit fitting space in which the electrical-part mounted unit tightly fits, while the dummy connector housing defines a connector fitting space in which the connector of the wire harness tightly fits. At a location where the unit holder and the dummy connector housing adjoin to each other, the unit fitting space and the connector fitting space are communicated with each other and partially overlap one another at an overlapping space. When the electrical-part mounted unit is fitted into the unit fitting space, the overlapping space is occupied by a corresponding portion of the electrical-part mounted unit. The corresponding portion of the electrical-part mounted unit forms the blocking means in cooperation with the overlapping space defined by the unit holder and dummy connector housing.
When the electrical-part mounted unit is attached to the unit holder of the electrical connection box according to this preferred embodiment, part of the unit occupies the overlapping space, that is, part of the connector fitting space of the dummy connector housing, so that the connector will not be mistakenly fitted in the dummy connector housing by a worker and the connector will be reliably connected to the electrical-part mounted unit.
Preferably, the unit holder has at one side a first opening into which the electrical-part mounted unit can be inserted and has at the side opposite to the first opening a second opening and a locking portion with which the electrical-part mounted unit can abut. In this case, the electrical-part mounted unit can be reliably attached to the unit holder of the electrical connection box through the first opening and the wire harness connector can be easily connected to the electrical-part mounted unit through the second opening.
Preferably, a dummy connector adapted to be connected with the connector of the wire harness is arranged in the dummy connector housing. In this case, the wire harness connector can be reliably held by the dummy connector.